Beltsville Brings Science to the Farm
istics are the same: any differences in growth
must be due to environment or feeding.
I saw one twin that was big and handsome,
while his brother was a scrawny runt. The
first had been fed a full ration, while the other
received only enough to stay alive.
After six months the second calf is full-fed.
Scientists then measure how much time and
feed it takes to bring the animal up to weight.
Streamlined pigs grow in Beltsville swine
barns. Seven new strains have been developed
there by selective breeding through the past
18 years.
Six of the new strains are based upon
crosses with the Danish Landrace breed. Each
is longer, leaner, and more meaty than the
American hog of old, yielding less unwanted
lard and more pork, ham, and bacon.
Breeders have even produced dark-skinned
sows that won't sunburn.
Their appetites
stay keen and their weight up, even in the
hottest summer sun.
In one barn hogs may eat as much as they
want, 24 hours a day. Contrary to the cliche
that condemns "eating like a pig," scientists
find that the hog never overeats.
Tailor-making Beltsville's Turkey
Beltsville is perhaps best known for its
undersized turkey bred to answer housewives'
demands for a bird that would fit today's
apartment-size refrigerators, small ovens, and
small families (page 209).
The compactness of the Beltsville Small
White turkey is the secret of its success.
Although it grows to little more than half
the weight of large gobblers, its breast is broad
and heavily fleshed, and the drumsticks are
both short and plump. Its quick-maturing
qualities and good breeding record make it
popular with growers.
The inside of an egg is of top importance
to poultrymen. Devotees of poached eggs
want a thick white to cover the yolk uni
formly. But if the housewife finds a blood
spot, she shies like a frightened horse.
Egg candling is still done by dexterous
packers who twirl each egg in front of a
powerful light. At Beltsville I saw a new
electronic candler, still under development.
High-intensity filtered light is shot through
the egg. If a blood spot is present, an elec
tric eye "sees" it, and the offending egg is
discarded.
Another tireless machine developed here in
1952 automatically separates eggs by the
slightest variation in the color of their shells
from pure white through various shades of
brown (page 201).
The machine got confused only when engi
neers ran through a few light-blue eggs of
the Araucana chicken of Chile. The eggs were
whisked into the light-brown basket-not a
serious mistake, since chickens which lay
naturally colored Easter eggs are a breeders'
rarity in this country.*
A Secret of Growth from Chicken Feed
In long, low poultry houses at Beltsville
ultraviolet lights burn all night. Installed
originally for their germ-killing power, the
dim blue tubes were soon found to be boosting
egg production. Scientists still aren't sure
why. This ultraviolet "prodding" is distinct
from the egg-laying stimulus of ordinary in
candescent light, a technique long familiar to
poultrymen.
Researchers know by recent experience that
startling discoveries sometimes come from such
small clues. A few years ago the hunt for a
better chicken feed put scientists on the trail
of a new vitamin with amazing power to pro
mote growth.
During World War II, animal-protein feeds
such as fish meal or slaughterhouse scraps be
came scarce. Soybean-oil meal, rich in pro
tein, was substituted on poultry farms. It
made a nourishing feed, but something was
missing. If no animal protein was present,
the hatchability of eggs dropped, and chickens
grew too slowly.
Because the first stomach of a cow is known
to manufacture vitamins, experimenters added
a little dried cow manure to the feed. Sud
denly birds thrived. Chemists found a growth
factor in the manure, but it was none of the
known vitamins.
At that point a pharmaceutical firm, Merck
& Co.,
announced its discovery of vitamin
B-12. The ruby-red crystals could greatly
stimulate growth, it reported. Beltsville tried
B-12 on chickens, and it was found to be the
missing factor.
As little as 18 billionths of an ounce of
B-12, injected into the fertile egg of a hen
fed a diet deficient in the vitamin, produces
astonishing results in newly hatched chicks.
At the age of five weeks they are nearly twice
the size of brother and sister chicks hatched
from untreated eggs.
Battling Animal Ailments
More recently, researchers in many labora
tories discovered that some of the miracle
working antibiotics stimulate animal and poul
try growth. Today aureomycin, terramycin,
and penicillin are being added to feeds in
minute quantities. Baby chicks and young
pigs grow faster and fatter on such wonder
drug feeds.
An early task of the Department of Agri
* See "Easter Egg Chickens," by Frederick G. Vos
burgh, NATIONAL GEOGRAPHIC MAGAZINE, September,
1948.
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